Of this genus there may be more than one species; but the best known is the Killer Whale, O. gladiator (Fig. 180, p. [341]), often spoken of as the "Grampus."[[248]] It is marked with contrasting bands of white or yellow upon a black body-colour. The animal grows to a considerable length, as much as 30 feet. Orca is a powerful and rapacious Whale; and Eschricht has stated that from the stomach of one, thirteen Porpoises and fourteen Seals were extracted. They will also combine to attack larger Whales, and Scammon has related how he witnessed such an onslaught upon a Californian
Grey Whale. "Belua truculenta dentibus," observed Olaus Magnus of this Cetacean. The high dorsal fin has been much exaggerated in old drawings; it has been even represented as strong and sharpened at the end, so as to be capable of ripping open the belly of a Whale. The fact that it sometimes lies over a little to one side is responsible for another anecdote: that an example of this Whale was seen to retire with a couple of Seals tucked away under the flippers, another grasped by the dorsal fin, and a fourth in the mouth! "When an Orca pursues a whale," wrote Dr. Frangius, "the latter makes a terrible bellowing like a bull when bitten by a dog." It is probable, according to F. Cuvier, that this Whale is the "Aries marinus" of the ancients, certain bands of white upon the head giving an impression of curved horns. It may also be the "horrible Sea-satyre" of Edmund Spencer.
Allied to Orca, but distinguishable from it by some rather minute peculiarities, is Pseudorca. It may be thus defined:—Teeth eight to ten, much like those of Orca. Dorsal fin rather small, falcate. Vertebral formula C 7, D 10, L 9, Ca 24. Six or all the cervicals united. The curious fact about this Whale, which embraces only a single species, P. crassidens, is that it was first known in the fossil condition from remains discovered in the fens of Lincolnshire. An important day for cetologists was that on which a whole herd entered the Baltic and furnished material for a better study of this Whale. It is not, any more than its near ally Orca, confined to northern seas; for several examples, at first relegated to a distinct species (P. meridionalis), have been obtained from the seas round Tasmania.
Orcella (which has been written Orcaella) has fourteen to nineteen small sharp teeth in each half of each jaw. The pterygoids are widely separate. The dorsal fin is small and falcate. The vertebral formula is C 7, D 14, L 14, Ca 26. Seven ribs are two-headed, and five of them reach the sternum.
This genus contains but a single species, O. brevirostris, which is both marine and fresh-water in habit; it occurs in the Indian seas, and in the Irrawaddy even as far up as 900 miles from the sea. Some regard the fresh-water individuals as a distinct form, O. fluminalis.
Sagmatias is a genus known only from a skull, which is remarkable for the elevation of the premaxillae into a crest; the
pterygoids are short, and there are thirty-two teeth in each half of each jaw.
Feresia is known from two skulls which are provided with ten to twelve teeth in each half of each jaw. It is intermediate between Globicephalus, Grampus, and Lagenorhynchus, according to Sir W. Flower.
The genus Delphinus contains the Dolphin, D. delphis.[[249]] The genus may be characterised as follows:—Teeth small and numerous, forty-seven to sixty-five. Vertebral formula C 7, D 14 or 15, L 21 or 22, Ca 30 to 32. The atlas and axis are fused, the rest free. The palatal border of the maxillae is deeply grooved. The fins are falcate; the beak long and distinct.
The Common Dolphin of the Mediterranean shows so many variations of colour, slight differences in the proportions of the bones of the skull, and in the number of the teeth, that it has been divided up into at least seventeen "species." But M. Fischer, who has studied many of these forms, does not admit them, and most students of this group of mammals follow him in the matter. The Dolphin is and has been the most familiar of Cetaceans; in consequence it has accumulated much anecdote of a mythical character. The extreme intelligence and goodwill towards man assigned to this creature by the ancients are possibly due to the anomaly of a creature ostensibly a fish showing many of the characters of higher animals. Its unfishlike intelligence baffled the early observers, who at once endowed it with especially advanced attributes. Hence the stories of Arion and others. The leaping of the Dolphin out of the water is exemplified in many Mediterranean coins and coats of arms; the heraldic dolphin is represented with an arched back as in leaping. The Dolphin reaches a length of some 7 feet, and appears to be world-wide in range. Possibly distinct is D. longirostris, characterised, as the name denotes, by the very long beak; it has also more teeth and is a native of Malabar. D. roseiventris again may be a third species of Delphinus. It comes from Torres Straits, and has the under parts rosy in colour.